Field of the Invention
The present invention relates to airport and prison security scanners, and more particularly, to a system for detection of illegal substances/narcotics smuggled inside internal cavities of a passenger or visitor to a secure facility.
Description of the Related Art
Currently, security systems at airports, secure facilities and other public areas use microwave or X-ray scanners with penetrating or reflected radiation. These scanners are used for scanning passengers (for example) and detecting prohibited or illegal objects located on a body of the passenger or inside the passenger without a manual pat down or search. A conventional scanner displays objects on an operator's screen and the operator has to perform a visual review of the screen images and to make a decision on whether to allow a person through or to perform additional manual search or scanning. However, this conventional approach is somewhat slow, inefficient and is heavily dependent on the operator who can get tired by the end of his shift, and make wrong decisions and miss some objects on the screen. Therefore, a method for automated analysis and detection of prohibited objects and illegal substances is needed.
Existing systems and methods are inefficient for detection of narcotics being smuggled inside person's stomach. U.S. Pat. No. 8,437,556 describes shape-based object detection and localization system. The separate objects are segmented on an image and are classified based on geometrical parameters and appearance similiarity to suspected objects. This method cannot be used for detection of drugs located inside the stomach cavity, because the images cannot be segmeneted due to a low contrast of the drug filled packets with the surrounding area of the stomach. In other words, these packets cannot always be reliably distinguished on the image without considerable manual effort.
US Patent Publication No. 20150010128 discloses a method for finding liquids inside the luggage. The proposed method uses segments of the objects and uses their atomic number acquired by dual-energy method. However, this approach cannot be used for detection of drugs located inside the stomach. An automated method for detection of hidden objects using microwave scanners is described by U.S. Pat. No. 8,774,461. The proposed method analyses a set of consecutive images of a surface of a human body. However, this method cannot be applied to detection of drugs located inside a human body, because the method is based on detection of humps and valleys on a image of a surface of a human body.
Another automated detection method is disclosed in publication by Mery, D., Automated Detection of Welding Discontinuities without Segmentation, Materials Evaluation, p. 657-663 (2011). This method detects welding defects by a sliding window method. However, the stomach area has many abnormalities and produces visual noise, which does not provide reliable information without additional filtering of data provided by the window classifier.
Accordingly, there is a need in the art for an effective method for an automated detection of illegal substances smuggled inside internal cavities of a human being, particularly inside his digestive tract.